A microwave hybrid IC is known, which IC comprises a multilayer printed circuit board with a flat flexible insulating layer on which a number of conductive contacts are made for connection to the leads of the modular circuit components or to the holder. Interconnections between the contacts are attained by means of conductive jumpers arranged in a single or several planes inside the multilayer printed circuit board at the places of installation of modules or holders of the circuit components. A number of holes are made in the flexible dielectric material. A separate rigid metal element serves to withdraw the heat from the circuit components. Said element is superimposed on the board in such a manner that the heat conducting metal projections entered the holes to get in touch with the modules or holders of the circuit components. Additionally, one or more rigid elements made also of a heat conducting material may be applied to the upper portion of the circuit components. Clamps are used to provide the contact between the metal projections and the circuit components.
Flexibility of the multilayer structure prevents the concentration of mechanical stresses resulted from difference between thermal expansion coefficient values of the multilayer structure and circuit components. The multilayer structure can be bent between the modules or holders, which betters the contact between the projections and the circuit components and minimizes the danger of tearing the latter off the board surface (GB, A 2,129,223).
However, the aforecited hybrid IC is possessed of unsufficiently high weight-size and electrical characteristics.
Known in the art is a face-down semiconductor device, wherein metal cylindrical projected leads are formed on the chip. The chip surface except for the leads is coated with a layer of an insulating resin having a thickness equal to the height of leads. Chip-to-carrier bonding is effected using a solder filled up the lead cavity (JP, A, 57-57303).
The aforecited semi conductor device is possessed of low electrical parameters when used in the microwave range, which is due to the presence of large-area contact pads, e.g., 100.times.100 .mu.m, and, respectively large chips, e.g. more than 1.times.1 mm, whereas the most widespread chips in the microwave technique are those which sizes being of 0.5.times.0.5 mm (or from 1.times.1 to 0.08.times.0.08 mm), having contact pads, e.g., from 0.03.times.0.03 to 0.015.times.0.015 mm which is concerned with a trend towards a minimized spurious inductance.
Moreover, making a projection on the metal base having the size approximating that of the contact pad, and its accurate mounting in the board hole involves some difficulties, especially in the case of small-size chips.